Casting apparatus



F. H. VALLENDER.

CASTING APPARATUS. APPLICATION FILED JAN. 29. 1920.

1,343,01 6. Patented June. 8, 1920.

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FRANCIS H. VALLENDER, OF ARLINGTON, MASSACHUSETTS.

CASTING APPARATUS.

rename.

Specification of Letters Patent.

Patented June 8, 192d.

Application filed January 29, 1920. Serial No. 355,015.

Be it known that I, FRANCIS H. VALLEN- DER, a citizen of the UnitedStates, residing at Arlington, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Casting Apparatus, of which the following is a specification.

This invention relates to apparatus for forming metal castings, usually of gold, and of small size, the casting being, for example, an inlay or filling for a cavity formed in a tooth.

It is customaryto-form such castings in a.

mold cavity formed in a body of investment material contained in a flask, the metal bearms lefand 15, fixed to the cylinder, and a ing melted on the top surface of the investment and caused, partly by suction and partly by pressure, to accurately fill the mold.

The object of the invention is to provide a casting apparatus adapted to be conveniently operated to exhaust air from one end of an investment and apply pressure to the opposite end.

- The invention is embodied in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings forming apart of this specification Figure 1 is a side elevation of a casting apparatus embodying the invention, the piston and platen hereinafter described bein depressed. a

ig. 2 is an enlarged longitudinal section, showing the piston and platen raised, parts of the apparatus being omitted.

Fig. 3 is a view similar to Fig. 2, showing the piston and platen depressed.

Fig. 4c is a sectional view, showing the flask and investment in an inverted position, and illustrating a part of the operation of forming the mold cavity.

The same reference characterswindicate the same parts in all of the figures.

The supporting structure or portion of my improved apparatus includes a cylinder 12, a flask seat 13, attached to one end or head of the cylinder, and suitable means for maintaining the structure in a predetermined position. I have here shown said means embodied in .a clamp composed of two thumb-screw 16 engaged with a tapped orifice in the arm 15, 'said clamp being adapted to engage a bench 17; The flask outer end of the air duct. carrier which is movable in a path parallel body 37 of attached, are provided with an air duct 18 constituting the air intake of the cylinder, the seat being adapted to support a flask 19 containing an investment 20, with the inner end of the investment extending across the 21 represents a with the axis of the cylinder, and is preferably an elongated rod, movable in suitable guides on the'supporting structure. Three guides are here shown, viz., a lower guide 22, an upper guide 23, formed on a standard 24:, and an intermediate guide 25.

26 represents a piston having a working fit in the cylinder 12, and rigidly connected with the carrier 21 by a piston-rod 27, and an arm 28,

29 represents a platen rigidly connected with the carrier by an arm 30, and located above the flask seat. 13. The piston and platen are'movable in unison by the carrier, and are so spaced apart that when the carrier is'raised to raise the piston from the lower end of the cylinder, the platen is raised above the flask and the investment therein, as shown by Fig. 2, and when the carrier is depressed, the platen will come in contact with the top surface of theinvestment before the piston reaches the down-- ward limit of its movement.

The carrier may be raised and lowered by any suitable means, and preferably, by a manually operable lever32, pivoted at 33 to the carrier, and at 34 to one end of a swinging fulcrum link 35, the opposite end of which is pivoted at 36 to a fixed car on the supporting structure.

When the piston and platen are raised, a

gold is deposited on the cupshaped upper end of the investment 20, and melted by a blow-pipe flame, or otherwise.

Prior to this operation the investment is provided, in any suitable manner, with a mold cavity 38 and an ingate 39 leading to the cavity. The carrier is then depressed and causes the piston to exhaust air from the porous investment, thus creating a suction which tends to draw the molten metal into the mold cavity. Before the piston reaches the downward limit of its movement, a body 29 of compressible refractory "material, such as asbestos, forming a part of the platen, is pressed against the top surface of the investment, so that for a brief period, and while the body 29 is being compressed 7 against the. top

1 19, closing its lower end by a concave-convexboth suction and head 42, to which is detachably secured a sprue 43 and a wax model 44, inserting the investment in the flask, removing the head and sprue, and finally causing the investment to absorb the wax model. The head 42 forms a concave or cup-shaped outer end on the investment, adapted to hold the metal .body 37.

. cylinder,

I claim: Y 1. A casting apparatus comprising a supporting structure, including an air pump cylinder, and a flask seat on one end of the said head-and seat having an air duct constituting the air intake of the cylinder,, a carrier movable relatively to said with said a piston and a platen connected structure,

carrier and movable 1n umson cylinder, said piston and thereby, said piston being adapted to exhaustair into the cylinder-from an investment in a mold flask supported by said seat, and the platen being adapted to exert downward pressure on said investment, and means for movingsaid carrier to simultaneously move the platen and the piston.

- 2. A- casting apparatus comprising a supporting structure, including" an air pump cylinder, a flask seat on one end of the cylinder, and a clamp adapted to engage a bench, said head and seat having an air duct constituting the air intakeof the cylinder,

an elongated carrier movable longitudinally in guides on said structure, in a path parallel with the axis of the cylinder, a piston within the cylinder, and a platen above the I platen being rigidly connected with the carrier, a manually movable lever porting structure said lever.

In testimony signature.

whereof I have. afiixed my pivoted to the carrier, and a fulcrum link plvoted at one end to the sup-. and at the opposite end to 

